There has been a lot of misconception revolving around the number of axles common passenger cars have. Although the design has changed over time, the number of axles remains the same.
Passenger cars have two axles, one for each set of wheels. Despite many design changes over the years, the way axles are counted remains the same. Look at the vehicle from the side, and count the number of wheels – that’s how many axles the vehicle has.
What is an Axle?
The central shaft for rotating wheels is called an axle. If you take a look at a toy car or a railroad train, you’ll see the axle in its simplest form – just a metal rod connecting two wheels together to create a wheelset. The design has evolved considerably over the years to suit different purposes. This article will focus on automotive axles, but we’ll also touch upon the other designs to give you a better idea of how it works.
Types of Axles
Car axles can be categorized by their position into the front and rear axles, but also by their function. The primary job of an axle is to endure the weight of the vehicle and transfer it to wheels. A horse-drawn or modern trailer can have one or more dead axles, which do not rotate with the wheels. Live axles rotate to transfer power to the wheels.
This is where the front-wheel, rear-wheel, and all-wheel drive terms come from. The most common type of live axle is the continuously variable (CV) axle.
The main confusion involving car axles comes from the stub axle design. With a stub axle, the left and right wheel are not in a direct connection, so there are technically two axles. However, we still count the number of axles from the side, making the existence of two separate axles irrelevant.
Stub axle is commonly used on the non-driven wheels of a car – stub front axle on a rear-wheel-drive car, or stub rear axle on a front-wheel-drive car.
Common Axle Problems
Learning the symptoms of common axle problems is of great value to any car owner. In this section, we’ll go through the list and explain how to identify, and fix the issues.
The most common axle problem is the loud clicking or crunching coming from the left wheel when turning left, or the right wheel when turning right. This is caused by bad CV joints.
The name comes from the fact that CV joints can continue to send power to the wheels even when turning and crossing uneven terrain. It’s imperative to replace worn CV joints at the first signs of wear as it’s a serious safety hazard.
There are several causes for vibrations in a car, a problem we’ve covered in great detail in the Reasons Why Your Car Vibrates Between 30 & 40 mph & 60 mph article. A failing CV axle is one of the suspects, so have your vehicle inspected if you experience excess vibrations when driving.
Grease on the Wheels
The CV joint has a rubber cover that keeps the lubricating grease contained. When it cracks, the grease will slowly come out, greasing up the rims and tires of the car. The car can be used until there’s not enough grease left, but this short timeframe is best used on a trip to the mechanic, and saving yourself the time and money on calling a tow service.
Does a car have 2 or 4 axles?
Don’t get confused by the design – cars will always have two axles. Looking at the car from the side and counting the number of wheels is still the best way to do it.
What happens if my axle breaks?
Axle breaking can result in loss of control and the corresponding wheel will be cut off from the power. This is one of the most drastic failures that only happens due to serious neglect of the vehicle, or in case of a collision.
How much is it to replace an axle?
The cost of an axle varies greatly on its type as well as the make, model, and year of your car. The rough estimate is between $500 and $1000, with labor being another $100 to $200.
Is 4WD safer than 2WD?
Because 4WD sends power to all wheels, it makes it more difficult to lose control over the vehicle at excessive speeds. Front-wheel drive vehicles tend to oversteer, while rear-wheel drive vehicles understeer. Four-wheel drive vehicles slide, which is probably the best out of the three. However, you should never let yourself get into that situation.
What is a 4 by 2 car?
This term doesn’t get used for cars, but rather trucks and SUVs. The first number states the number of wheels on a vehicle, while the second relates to the number of driven wheels. This also works for 4×4 or 4×2 labels.
If you’re walking away from this article with clear knowledge of how many axles are on a car, I’ve succeeded in my mission. To learn more about vehicle parts, how to replace them, and money-saving tips, check out our other articles!